Tissue-CRF is a potent and specific corticotrophin releasing factor that produces prolonged hypersecretion of the pituitary-adrenal system. Studies will be continued to attempt to separate and characterize its chemical nature and to determine its source of origin. A comparison will be made of the dynamics of ACTH secretion of pituitaries in vitro when they are activated by either hypothalamic CRF or Tissue-CRF. In Vitro superfusion systems will be employed to study the dynamics of pituitary-adrenal secretions and to monitor patterns of hormone secretions. BIBLIOGRAPHIC REFERENCES: Brodish, A.: Hormonal and Behavioral Influences on the Circadian Rhythmicity of the Hypothalamic-Pituitary-Adrenal System, in Biological Rhythms in Neuroendocrine Activity, ed. by M. Kawakami, Igaku Shoin Ltd., Tokyo, 1974, pp. 253-266.